Reversible hammer mill with mate



March 4, 1952 J. G. WILSON 23,468

REVERSIBLE HAMMER MILL. WITH MATERIAL DEFLECTING FEED STRUCTURE Original Filed Feb. 17, 1948 2 SHEETS-SHEET l March 4, 1952 J. G WILSON 23,468

REVERSIBLE HAMMER MILL wrra MATERIAL DEFLECTING FEED STRUCTURE 2 SHEETS-SHEET 2 Original Filed Feb. 17, 1948 I N VEN TOR.

Reissuerl Mar. 4, 1952 REVERSIBLE HAMMER MILL WITH MATE- RIAL DEFLECTING FEED STRUCTURE John Gilmore Wilson, Malvern, Pa., assignor to Pennsylvania Crusher Company, Philadelphia,

Pa., a corporation of New York Original No. 2,514,111, dated July 4, 1950, Serial No. 8,831, February 17, 1948. Application for reissue July 6, 1951, Serial No. 235,507

3 Claims.

Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specification;

This invention relates to reversible hammermills for instance as illustrated in the patent of W. A. Battey No. 2,149,571 issued March 7, 1939, and of Stanley D. Hartshorn No. 2,170,407 issued August 22, 1939.

It is an object of this invention to provide a reversible hammermill of this type having means for arresting the escape of dust and deflecting particles from passing out through the entrance feed.

These and other objects of this invention will be better understood from the following detailed description of the specific embodiment with reference to the accompanying drawings of which;

Fig. 1 is a sectional view of the upper part of a reversible hammermill showing the dust arrester; and

Fig. 2 is a side sectional view of the reversible hammermill taken on line II-II of Fig. 1.

The machine shown in Figs. 1 and 2 comprises a frame I0 which supports and encloses the crushing machinery.

Supported within the frame I0 is a cage II formed by left breaker plates I2, I3 and I4 and right breaker plates I6, I1 and I8, and screen bars I9 and 2|, and frame liners 22. The screen bars I9 and 2I are pivoted on cage hinge shafts 23, and enclose a hammer mechanism 24. The hammer mechanism 24 is composed of hammers 26 fastened on a rotary shaft 21 through disks 2B and hammer suspension bars 32. The disks 28 are regularly spaced along shaft 21 by spacers 29 and the disks 28 at each end abut against collars 3| on the shaft 21. The hammer suspension bars 32 extend longitudinally through suitable holes in the disks 28 at regularly spaced intervals around the circumference of these disks. The hammers 26 are pivoted on the bars 32.

The frame I0 has a hopper or feed chute 33 centrally positioned on its upper side to feed material to be crushed through a hopper liner 34 into the cage I I above the hammer mechanism 24. The shaft 21 is suitably driven by means not shown to rotate the hammers 26 in either direct on.

The breaker blocks are arranged symmetrically on each side of the cage I I to receive the material to be crushed upon rotation of the hammer mechanism 24 in either direction. Material introduced through hopper 33 is crushed and reduced in a manner illustrated and discribed in U. S. Patent No. 2,170,407 to Stanley D. Hartshorn issued August 22, 1939.

As the hammers 26 rotate and crush the material small particles of dust formed during the matter printed in italics indicates the additions made by reissue.

crushing operation are thrown or rise from the crushing operation and escape through the hopper 33. According to this invention, to prevent this escape of dust and other small particles, a plate 36 is provided which abuts against the upper breaker block I2. This plate 36 has arms 31. Each of the arms 31 receives a shaft 38 which extends from the side of the frame I0 passing through suitably provided apertures in the frame I0 and the hopper liner 34. The baflle 39 comprising the plate 36 and the arms 31 is centered in the upper part of cage II immediately above the hammer mechanism 24 and with a minimum clearance above the outermost extremity of the path of the hammers 26. One side of the plate 36 abuts against the upper breaker block I2 and extends into the cage II obliquely at an acute angle to the vertical dimension of the hammermill and substantially perpendicular to a tangent to the path of the hammers 26. An arm M is fastened on the outer end of one of the shafts 3I and suitably spaced away from the frame I0 by a sleeve 42. The arm M is provided at its end with a bracket 43 suitable for securing the arm 4| in place. The cage II above the hammer mechanism 24 is symmetrical and spacious so that the hammers may rotate in either direction and impact the material to be crushed on either side. The impacting zone at the top of cage II is thus divided into a chamber 46 on the right side as shown in Fig. 1 for the impacting upon clockwise rotation of the hammer mechanism 24 and a chamber 44 on the left side as shown in Fig. 1 for impacting upon counterclockwise rotation of the hammer mechanism 24. The shafts 38 turn in the hopper liner 2I and the frame II) to swing the plate 36 into contact with either the breaker block I2 in the chamber 46 or the breaker block I6 in the chamber 44. The bracket 43 is fastened to frame I0 by suitable means not shown so as to hold plate 36 close to one or the other of the breaker blocks I2 and I6.

The baffle 39 may be set with the plate 36 close to or abutting either breaker block I2 or breaker block I6. As shown in Fig. 1, the baffle 39 is fastened with the plate 36 abutting the left breaker block I2 in chamber 46. In operation the hammers 26 engage the material to be crushed which is fed through hopper 33 into the cage II and as shown in Fig. 1 is impacted and thrown against the right breaker blocks I6, I1 and I8 for reduction. As described in the Hartshorn Patent No. 2,107,407 above referred to, the material is further reduced and removed from the hammermill by screen bars I9 and 2| of the cage 3 II. The rapidly moving hammers 26 rotating in the cage ll produce a current of air which, travels upward with the rising side of the hammer mechanism 24. This current of air enters the large impacting zone and sweeps tangentially from the circle of hammer rotation roughly following the contour of chamber 46. In the absence of the device of thi invention the current of air escapes from the chamber 46 passing upward and out through the feed hopper 33 causing a back draft out of the hopper which retards the feeding of uncrushed material. Dust formed during the reduction operation and carried around in this current of air also passes out through hopper 33. At the high operational speed of the hammermill small particles are thrown oif tangentially from the hammers. Some of the particles that are thrown off when the hammers are passing through the upper portion of the case H fly upward into the hopper 33 and also escape out of the top. This back draft and escape of dust and small particles is objectionable.- As provided for by this invention in prevention of these objections, the plate 36 extends across the chamber 46, as shown in Fig. 1, from the breaker block I2 to a line immediately adjacent the outer diameter of the path of the rotating hammers 26. The plate 36 together with the chamber 46, as shaped by the breaker blocks I2 and I5, form a recess in which the upward travelling current of air from the hammers 26 sweeps around in a semicircle and is deflected by the plate 36 away from the hopper 33 and back into the circle of hammer rotation where it becomes part of the air travelling with the hammers 26. they pass the lower edge of the plate 36 reduce the pressure on the side of the plate 36 near the hopper 33. The reaction from this lowered pressure increases the down draft through the hopper and further inhibits escaping particles. On the other hand, the baffle 39 constricts the air current passing through the chamber 46 to build up a pressure on the opposite side of the baflle 39 in the chamber 46. This pressure, tends to back up into the-screen bar sector of the cage H and force the air to escape through the screen bars [9 and: 2| and thus cut down the volume of air which tries to force its way into chamber 46 and, out through. hopper 33. Small particles tangentially'catapulted from the hammers 26 strike the plate 36 when released in the chamber 46 and are deflected downward toward the screen. bars l9 and 2|.

When the hammermill is reversed 50 that the hammers run ina counterclockwise direction an identical operation of the baflle 39 may be obtained by reversing its position to the right. of cage II in chamber 44, as shown in Fig. 1, and into engagement with the breaker block l6. The bracket 43 is suitably fastened in this position and the above described operation of the hammermill will be obtained in the reverse direction.

' The plate 36 in addition to deflecting inwardly the dust particles rising from below also will serve to deflect the particles of the material to be crushed introduced through hopper 33. This is of advantage as in a hammermill the penetration of the crushed material beyond the outer edge of the face of the rotating hammer isimport-ant in reducing the attrition on the hammerand consequently lengthening its life. The plate 36 engaging the material as it comes through the hopper 33 and deflecting it to a place of en- Concomitantly, the hammers 26 as gagement with the hammers 2.6, which place of engagement is behind the place where the material would engage the hammers were it not for this deflection, permits the material to drop further down onto the face of the rotating hammers 26.

This invention prevents the dust and small particles, formed when material such as coal is broken in a hammermill, from rising back out of the feed hopper and at the same time dpes not impede the feeding of the material to the hammers. Thus it separates the objectionable back draft of air, dust and small particles from the descending feed'and directs both into the rotor. A hammermill operating without the device of this invention permits. objectionable. dust. and smallparticle's to escape from the feed hopper. The advantage of this invention is that the battle reduces the back draft of air and deflects the current of dust-carrying air and small particles thrown off from the hammers back into the hammers from which they pass out through thescreen bars lfland 2i. Therecesses formed by the walls of the chambers 44 and 46 in combination with the plate 36 is advantageous as it swirls dust-carrying, air current around and back into the circle of hammer rotation without forcing the current of air to seek outlet elsewhere. The lowered pressure in the hopper further inhibits escaping particles. The device of this invention is also advantageous in its reversibility which places it in the most advantageous position during the operation of the hammermill in either direction and removes it from the path of the impacted material when not used on that side of the hammermill.

It is to be understood that the bafile may consist simply of a plate; placed in position to deflect the particles and back draft and create a, down draft. The manner, as described, of positioning the bafile will suggest various ways of which the battle may be moved or arranged. It will be apparent to those skilled in the art that various modifications can be made without departing from the principles of the invention as disclosed herein and for that reason. it. is not intended that it should be limited other than by the scope of theappended, claims.

What is claimed is:

1. In a crusher a rotor having hammers adapted to receive and. impact material. entering vertically downward at top center of. the hammercircle, a feed; chute radially above said center and having its lower end in a definite fixed position spaced. from the hammer circle to provide an intermediate chamber for central radial supply of the material from the chute into said. hammer circle, a stationary breaker plate structure beginning at least at the said stationary lower end. of said, feed. chute and extending along, thesid'e of, said, chamber, anda deflector plateat the side of said chamber interposed between: said rotor and. said breaker, plate andv extending from said breaker plate inward to a point immediately adjacent said hammer circle to intercept material from the side, of said chamber and direct it inwardv into the hammer circle.

2. A crusher as set forth in claim 1 in which the rotor is reversible with breaker plates on each. side of said chamber and the deflector is mounted on a movable support positioning said deflector interchangeably in: said intercepting position at each side of. the: chamber.

3. In d, crusher a, casing, a. rotor hoping a plurality of spaced pivoted hammers and adapted to be driven alternately in opposite directions and receiving and impacting material entering radially into the hammer circle when driven in either of said directions, said rotor being driven at a speed in each direction of rotation developing currents of dust-laden air directed outward from the hammer circle, a structure for passing material to said rotor comprising a feed chute having its center in the generally vertical plane of the rotor axis and delicering the material substantially radially into the hammer circle on both sides of said plane for each direction of rotation of said hammers and means adjacent the delivery end of said feed chute forming a crushing chamber within the casing intervening between the delivery'end of the feed chute and said hammer circle and having walls spaced from said hammer circle on both sides thereof andcomprising plate means positioned in said chamber at a position on one side thereof where the hammers are approaching alignment with the near side of the said feed chute and extending downward and inward on one side to a point immediately adja cent said hammer circle and spaced from said center plane of the feed chute and generally in alignment with the near side of the said radial feed into the hammer circle to intercept material carried upward by said hammers on the near side of said chamber and direct it inward into the hammer circle for a corresponding direction of rotation of said hammers, said plate means being adjustable to similarly extend inward to a point immediately adjacent said hammer circle on the other side of saidchamber where the hammers are approaching alignment JOHN GIIMORE WILSON.

REFERENCES CITED The following references are of record in the file of this patent or the original patent:

UNITED STATES PATENTS Number Name Date 640,845 Webster Jan. 9, 1900 675,751 Moustier June 4, 1901 1,043,513 Dell Nov. 5, 1912 1,049,712 Helbig Jan. 7, 1913 1,086,868 Stimpson Feb. 10, 1914 1,339,950 Fowler May 11, 1920 1,673,465 McLaughlin June 12, 1928 1,769,867 Stoner July 1, 1930 1,997,214 Guest Apr. 9, 1935 2,122,965 Swenson July 5, 1938 2,149,571 Battey Mar. 7, 1939 2,170,407 Hartshorn Aug. 22, 1939 2,171,100 Sakural Aug. 29, 1939 2,287,799 Hartshorn June 30, 1942 2,440,388 Wright Apr. 27, 1948 2,463,631 Knight Mar. 3, 1949 2,491,661 Gruendler Dec. 20, 1949 FOREIGN PATENTS Number Country Date 682,172 Germany Oct. 9, 1939 

